Miguel de Icaza: "To sum up: (a) First dimension: things change too quickly, breaking both open source and proprietary software alike; (b) incompatibility across Linux distributions. This killed the ecosystem for third party developers trying to target Linux on the desktop. You would try once, do your best effort to support the 'top' distro or if you were feeling generous 'the top three' distros. Only to find out that your software no longer worked six months later. Supporting Linux on the desktop became a burden for independent developers." Mac OS X came along to scoop up the Linux defectors.

I'm not sure about that. I hope the real target demographic of most Linux distros will always have enough people to keep one or more usable distros around. And while the real target audience might not include average joe or his grandma, it hopefully includes enough devs for it to be OK for a while.